| Geyser | 1991-05-23 |
|---|---|
| Whistle | 1991-05-12 0000-1991-05-24 0000 |
| Values for Old Faithful Area | 1991-05-23 |
|---|---|
| Astronomical Twilight Begin | 03:35 |
| Nautical Twilight Begin | 04:28 |
| Civil Twilight Begin | 05:13 |
| Sunrise | 05:47 |
| Sunset | 20:52 |
| Civil Twilight End | 21:26 |
| Nautical Twilight End | 22:11 |
| Astronomical Twilight End | 23:04 |
| Moon Illumination | 74.96% |